The annual U.S. incidence rate of head and neck cancer is approximately 40,000 cases (Vokes et al., New Eng. J. Med., 328:184 [1993]). Although salivary gland tumors differ in their etiology, histology and standard therapy from most head and neck cancer, these cancers represent a significant threat to human health. Salivary gland tumors arise from either one of the three major salivary glands or from the minor salivary glands that line the mucosa of the upper aerodigestive tract. Histologically, these tumors are very heterogeneous, and include mucoepidermoid cancers, pleomorphic adenoma, and adenoid cystic carcinomas as the more frequent observed tumor types. Treatment of these tumors is predominantly surgical, with post-operative radiotherapy being frequently administered. For unresectable tumors, neutron irradiation has been used in place of conventional radiotherapy. Chemotherapy is typically reserved for patients with recurrent or metastatic disease.
Mucoepidermoid carcinoma (MEC) is the most common malignant human salivary gland tumor which can arise from both major (parotid) and minor salivary glands, including serous/mucous glands within the pulmonary tracheobronchial tree (Calcaterra, in Cancer Treatment, 4th ed. (Haskell, ed.), W. B. Saunders Company, Philadelphia, [1995], at pages 721–726). These salivary gland tumors may be deadly, due to their tendency to grow locally and recur aggressively, if not completely excised. However, complete excision is difficult due to the three-dimensional growth pattern of these tumors, which make it difficult for the surgeon to accurately determine when clean margins have been achieved. Pathologic analysis using light microscopy is currently employed to assess tumor margins and to help determine the need for post-operative radiotherapy. However, this approach does not necessarily provide sufficient sensitivity for optimal patient management. In addition, both surgeons and patients desire minimal surgical approaches for cosmetic reasons, as well as to preserve nerve function to the facial area. Thus, methods and compositions suitable for the rapid and reliable diagnosis of these and other aggressive tumors are needed.